1970 Mustang AJE front suspension conversion.

Finally got her on the scales last night in full race trim with me sitting in it. I wish I had a video of it leaving the line but anyway.

Total weight was 3087
front left was 863
front right was 865

rear left was 728
rear right was 632

total front was 1728= 55.9%
total rear was 1359 = 46.1%

The scales are some old circle track scales.
Front strut springs are 200.
Rear coilover springs are 110. Bought used and this is what the guy told me he thought.

Suggestions on new springs or weights or anything please???

I think i might try a softer front spring if it was mine.
I put a 200 under my truck but havent got it done or had to the track yet. (It should weigh around 37-3800)

dirt_worker wrote:I think i might try a softer front spring if it was mine.
I put a 200 under my truck but havent got it done or had to the track yet. (It should weigh around 37-3800)

Thanks, thats what Richter said earlier also. Is there a formula to get close on the springs? 150's??

Put a 150-160 on it

Very nice job, thanks for sharing.

richter69 wrote:Put a 150-160 on it

I definitely need to change something. I'll be posting some launch videos today finally. It looks bad..

67460 wrote:Very nice job, thanks for sharing.

Thanks.

Beyond rate there is free height or length of the spring. Measure the installed height as it sits with you or your weight equivilent in it (sand bags).

Do you know the free height of the 200# units in it now? Several of the companies athat sell springs, AFCO, Santhuff, QA1 etc. have charts of wire size and free coils (excluding the dead coils, the flat parts where the ground flat portion touches the coil above it) which determines the rate of the spring. Once you know how much the existing coils compressed with your current set up you know the effective load on the spring. For example 200#/in. springs that are compressed three inches when installed in the car from full extension to ride height means you have 600# load.

To go to 150# springs they will have to compress 4" to reach the same load (600/150) That also means they need to start out with a taller free height. So if the current springs are 10" you'd go to 12" on the 150's. You'd adjust the coil over for fine tuning ride height.

CDMBill wrote:Beyond rate there is free height or length of the spring. Measure the installed height as it sits with you or your weight equivilent in it (sand bags).

Do you know the free height of the 200# units in it now? Several of the companies athat sell springs, AFCO, Santhuff, QA1 etc. have charts of wire size and free coils (excluding the dead coils, the flat parts where the ground flat portion touches the coil above it) which determines the rate of the spring. Once you know how much the existing coils compressed with your current set up you know the effective load on the spring. For example 200#/in. springs that are compressed three inches when installed in the car from full extension to ride height means you have 600# load.

To go to 150# springs they will have to compress 4" to reach the same load (600/150) That also means they need to start out with a taller free height. So if the current springs are 10" you'd go to 12" on the 150's. You'd adjust the coil over for fine tuning ride height.

Thanks Bill, I'm hoping to get out there today and mess with it. I need to get all the measurements on the front suspension.

Amazing job! I love the feel of a more modern suspension in a classic ride

GSEninja wrote:Amazing job! I love the feel of a more modern suspension in a classic ride

Thanks. especially the steering.

I put some new 29.5X10.5s on the other day and took my EZ plate out,timing back in it and took the 100lbs of weight out of the trunk.

New best...
1.32 60ft.
6.01 1/8
9.49 1/4.

I'm happy but want more. More changes after two more races are over. Ive also been taking weight out between races this summer. The car was 3410 with me in it last October. It is now down to 3010 with me. I'd like to get another 200 out this winter. Windows and fiberglass plus some other areas...

Once I get the winter changes finished then we will scale it again and get the right suspension under this thing.


Thanks for all the help on this thread.

Nice job! I have a AJE setup in my 1970 fastback and I am building a 521 for strip / street action. Any advice since you have finished yours would be appreciated. 70FB did you have to fabricate the headers on the passenger side?